Firstco T4072 Strap-On Aquastat for 7/8" OD Tubing (37TC33)

The First Company T4072 Aquastat (37TC33) is a strap-on pipe-sensing temperature controller designed for use with 7/8-inch OD (3/4-inch nominal) copper tubing in hydronic heating and cooling systems. It automatically senses water temperature to govern system operation, enabling reliable two-pipe automatic changeover control in fan coil and air handler applications.

This aquastat is a factory-listed option for First Company HBC-series fan coil units and other First Company chilled water/hot water air handlers. It is the 3/4-inch nominal pipe version of the aquastat pair; the companion model T4071 fits 5/8-inch OD tubing.

Key Features:

• Strap-on design mounts directly to 7/8" OD (3/4" nominal) copper tubing — no pipe cutting required
• Senses pipe temperature to control system operation automatically
• Temperature changes at 95°F (±10°F) and resets at 65°F (±5°F)
• Rated for 10 amps inductive / 25 amps resistive / 60 amps locked rotor
• Red wire = cold signal; Blue wire = hot signal
• Mounting clip included for secure pipe attachment
• Style 43712 — OEM part for First Company systems
• UL Listed

The T4072 is essential for two-pipe hydronic HVAC applications where automatic changeover between heating and cooling modes is required. It is a direct factory replacement part for First Company fan coil units and air handlers, ensuring accurate, reliable temperature-based system switching.